Following training, each site photographer transfers test images for evaluation and feedback, then repeats as required, before they are permitted to capture study data. Image quality control is strictly governed by the imaging protocol and documented within 24 hours of upload, via image feedback to site users. Image feedback clearly identifies those images which pass or fail QC, explains the reasons why and actively encourages greater consistency through constructive support.

The combination of prompt image feedback and pro-active explanations minimises the necessity for re-training. If required however, early face to face (web–based) intervention proves most efficient in identifying and correcting the route cause.